Research On The Bilateral Control Strategy Of Master-slave Isomerism Tele-operation System

The master-slave tele-operation system with force tele-presence not onlytransmits the command of the operator to tele-robot, but also feedbacks the force andposition information of the slave side to the master side. Benefited from that way theoperator can obtain a sense of reality, as if he is directly operating at the slave side.Taking into account that the quality and efficiency of task completion depends ontele-operation system’s performance, therefore, how to improve the tele-presence hasbecome an important research topic.This M.E. dissertation was developed based on National Natural ScienceFoundation named “tele-operation of multi-degree electro-hydraulic servo parallelmanipulators with accurate force feedback”(No.50975118), and aims to research onthe control strategy of3-DOF master-slave isomeric tele-operation system. Byexploring the new control strategy theory and simulation results, and contrasting withtraditional control strategies, the foundation of improving force sense feedbacktele-operation master-slave servo control system’s operation performance is laid.This paper establishes3-dof parallel manipulator, OMEGA-3’s kinematicsequation and dynamics equation which adopts principle of virtual work, analyzeskinematics inverse solution and kinematics positive solutions which can be obtainedaccording to numerical methods. The performance index of OMEGA-3’s workspace,singularity, dexterity is also discussed. For force, displacement couplingcharacteristics of multi-DOF parallel manipulators, RBF neural network inversesystem method is developed for decoupling control of the master manipulator. Thelinear mathematical model of the slave manipulator’s electro-hydraulic servo controlsystem is also established as well as PD controllers and disturbance observercontrollers for optimization. A new control strategy is proposed from the view ofposition constraint space after analyzing the limitations of existing tele-operationsystem control strategy. According to combine master-slave joint space error andposition constraint space matrix instead of a constant gain, the local manipulatorbecomes reproduction of slave manipulator position constraint space rather than simply follows position and force signal. Thus, the operator can accurately perceivethe environmental conditions in the slave side. Simulation test is carried out under thesituations when the remote manipulator is in the state of free motion, load motion,obstructions interfering motion and motion subjecting to unidirectional force. Andsimulation results show that the new proposed control strategy is not only able toaccurately perceive the amplitude of feedback force, but also can determineinterference coming from which freedom and successfully perceive the direction offeedback force, therefore possessing better force tele-presence.